ROCHESTER, Minn., Nov. 17 (UPI) -- Patients who had gastric bypass surgery for morbid obesity run an increased risk of experiencing kidney stones, said researchers at Minnesota's Mayo Clinic.
The surgery seems to change urine's chemical composition in a way "that could favor the formation of kidney stones," said Dr. Rajiv Kumar of Mayo Clinic College of Medicine in Rochester, Minn., one of the study's authors.
Researchers said they found that patients who underwent gastric bypass surgery showed several chemical changes that are linked to a higher risk of kidney stones. The changes included an increase in oxalate -- a chemical that increases a kidney stone risk by binding to calcium -- and a decrease in citrate, which plays a role in dissolving crystals that can lead to stones.
"Our results suggest that individuals undergoing such procedures are potentially at increased risk for developing kidney stones," Kumar said, adding that gastric bypass patients may want to consult their doctors about diet and other steps they can take to reduce their risk of kidney stones.
The paper was presented during the American Society of Nephrology annual meeting in San Diego.
